Process for the production of 19-nor-4-pregnen-21-ol-3, 20-dione



United States 2,925,421 H PROCESS FOR THE PRODUCTI'iON or 9-ison-4- a R GNEN- -OL-EJG-DEW j Carl Djerassi, Birmingham, Mich, and Franz Sondheimer, Alberto Sandoval, and George Rosenkranz, Mexico City, Mexico, assignors to Syntex S.A., Mexico City, Mexico, a corporation of Mexico e No Drawing. Application January 25, 1955 1o Serial No.,484, 064 1 p Claims priority, application Mexico February '3, 1 954 c '5 clai (ClJZGfl- -397-4) e I The present invention relates. to novel 'cyclopentandf phenanthrene compounds and to a' novel process involving these compounds.

More particularly the present invention relates to'the production of A -19-nor-pregnen-2l-ol-3,ZO-dione ('19- hojpdesoxycorticosterone) and to novellintermediates"for the production thereof, The final products of the process of. the present invention, 1 9-nor desoxycorticosterone or its esters, are active cortical hormones having aihigher activity than the cortical hormone desoxycorticost'erone.

In accordance' with the presentinvention a novel meth:

0d has been discovered for, the preparation of 19-norv desoxycorticosterone from the known compound methyl 3-methoxy-1,3,5restratriene-17 carboxylate and involving as novel intermediates 17-hydroxy-methyl-A -estren-3 one and 3-keto-A -estren-l7-carboxylicacid 1 3-keto-19-noretiocholenic acid).

The novel process of the present invention may be exemplified by the following equation: coon Reduction and dd Hy l Alkali Metal Liquid 0:

' Ammonia Followed t 'by' Acid O d t in a ion lChromitr M13 (3001 9 (100B I Oxalyl E v 0= Chloride '0? Diazomethane lBoiling- Lower Fatty Acid $H2OAC- I C0 Q 7 In the above equation R represents a lower allcyljgroup preferablya methyl group.

, In practicing the process above outlined, a 3 hfydroxy-v alowe'r alkyl'ester and a lower alkyl ether, as for exboxylat'e (a known compound described by Djera'ssi and S cholz', J.-A,e.s;, 71, 3962, 119.49 isdissolve'd in anjinel t organic solvent'such as ether and mixed with liquid am- 'monia; There is thereafter added with continuous stirring an alkali metalpreferablyflithiumduring a substantial V period of time of the order of ZQ minutes. The stirring was thereaftefleontinued for a few more minutes and abso u e al ohol, W stt dd d prefe a ly i w incrementsf'spac'ed about 10 minutes apart, :The solutionwas tl' eniallow'ed to evaporateto dryness. ZWater 'was then d to the residueand the collected precipitate washed (until neutral. The precipitate of 17.-hydroxymethy1-"3; m thqxymfi WStradienQ not further purified but used vf "t e next teps f a id y y s.

h Y'dm Y wa Preferably dissolved in a lower alcohol solvent and hydrolysed by heating with acid preferably amineral acid such "as l 1ydrochlo'ric.' The resultant compound was the corresponding 17-hydroxymethyl-A -estren-3-one.

7 Upon oxidation with chromicacid preferably in acetic acid at room temperature hthe' :17-hydroxyrnethyl-A st fen-one compoundis' oxidized to theedrrsponding 'l'l carboxylic acid i.'e. 3-keto A }estren+17-carb0xylic acid. This last compound on treatment of the sodium salt with oxalylchloride at a low temperature ofthe order of 0 C, "fo r a period of timeof the order of three hours gave the correspondingacid chloride. Treatmentlof'the acid chloride with diazomethan e followed by treatment 'of'theproduct of this reaction with a lower fatty acid such 7 I a acetic thengave the desired lower fatty acid'ester of A4-19-nor-pregnen-21-o1-3,2 0-dione (the lower fatty acid.

ester of 19-nor-desoxycorticosterone). Obviously, these esters could be converted to the free compound by con;

ventional saponification. I

The following specific examples. serve toillustrate but are not intended to limit the present invention:

Example I 10 g. of methyl 3-methoxy-.1,3,5(10)-estratriene-17- carboxylate (prepared in, accordance with Djerassi and Scholz, J.A.C.S., 71; 1962. 1 949) was dissolved in 800 cc. of anhydrous ether and mixed with 1015 'cc. ofliquid ammonia. Under continuous stirring, this solution was treated in the course of'20 minutes with 15 got lithium metal. The stirring was continued for 30 minutes ('additional 10 minutes) and then cc. of absolute alcohol was added; after afurther 10 minutes 100 co. more of alcohol was added and the solution was allowed to evaporate to dryness- Water was added to the residue and the precipitate was collected and washed until neutral, "thus giving 9.6 g. with a melting point of 114-117 C.

9 g. of this product was dissolved in 450 cc. of methanol and mixed with 270 cc. of 3-norma1 hydrochloric acid. The mixture was, heated at 60 C. for 30 minutes and then poured into water The mixture was extractedwith three portions of ether and'the combined ether extract was washed with sodium carbonate solution'andwater until neutral and evaporated to dryness. Crystallization of the residue from acetone afforded 4.8 g. of 17-hydroxy- .methyl A -estren-3-one, with a melting point of 137 0. I V 1 V Example II A solution of 0.13 g. ofchromic acid in three drops and Water and 2 cc. acetic acid was added in the course of 10 minutes to a stirred solution of 0.5 g. of 17- hydroxymethyl-A -estren-3-one in 20 cc. of glacial acetic acid, at room temperature.

ethyl 3 methoxy -estradiene The stirring was continued fora further 10 minutes and the solution .was kept standing overnight, poured into water and the precipi tate was filtered and washed. The solid residue was digested with a' solution of potassium hydroxide; the soluble fraction was separated by filtration and the solution was acidified with hydrochloric acid. A precipitate separated from the acid solution which was collected and washed, thus producing 0.36 g. of 3-keto- A -estren-17-carboxy1ic acid with a melting point of 256259 C., [0:] 98 (chloroform).

Example III 0.492 g. of 3-keto-A -estren-17-carboxylic acid was dissolved in cc. of methanol. cooled to 0 C. and treated in the course of 30 minutes under continuous stirring with a solution of sodium hydroxide in methanol, containing 0.94 molar equivalents of the base (14 cc. of a 0.109 N solution). The solvent was removed under'vacuum and the residue was dried under vacuum for 18 hours. The sodium salt was triturated with 15 cc. of anhydrous ether, the mixture was cooled in an ice bath and then 2 cc. of recently distilled oxalyl chloride was added. fThe solution was kept for three hours at 0 C. and then evaporated to. dryness. Anhydrous benzene was added to the residue and again it was evaporated to dryness. This process was repeated twice.

The acid chloride thus obtained was dissolved in benzene and filtered. The filtrate was added under stirring to an ether solution of diazomethane (obtained from 5.0 g. of nitrosomethylurea) at a temperature'of -20 C. The solution was kept for one hour at 0 C. and then evaporated to dryness under reduced pressure.

The solution was The gummy residue was immediately treated with 20 cc. of boiling acetic acid and the solution was refluxed for three minutes, cooled and extracted with ether. The ether solution was washed to neutral, dried and evaporated to dryness. The residue was then chromatographed in a column with neutral alumina, and the fractions eluted with benzene yielded 176 mg. of the acetate of 19-nor- A -pregnen-21-ol-3,20-dione with a melting point of 153 159 C. Recrystallization from acetone afforded 132 mg. of the pure compound with a melting point of 168-'170 C., identical with a sample prepared in acoordance with the method described in our United States patent application Serial Number 390,723, filed Novemher 6, 1953, now Patent No. 2,861,085.

We claim:

1. A process for the production of a lower fatty acid ester of 19-nor-desoxycorticosterone which comprises reducing a compound of the formula:

COOR

acid to form 3-keto-A -estren-17-carboxylic acid, treating the last mentioned compound with oxalyl chloride to form the corresponding acid chloride and treating acid chloride with diazome'thane followed by heating with a lower fatty acid.

2. A process for the production of 17-hydroxymethyl- A -estren-3-one which comprises reducing a compound of the formula:

COOR

wherein R represents a lower alkyl group, with an alkali metal in liquid ammonia and hydrolysing the reduction product with acid.

3. The process of claim 2 wherein the lower alkyl groups are methyl groups and the alkali metal is lithium. V 4. Aprocess for the production of 3-keto-A -estrenl7-carboxylic acid which comprises oxidizing 17-hydroxymethyl-M-estren-3-one with chromic acid.

5. 17-hydroxymethyl-A -estren-3-one of the following formula: I

References Cited in the file of this patent UNITED STATES PATENTS 2,259,698 Johannessohn Oct. 21, 1941 2,309,408 Miescher Jan. 26, 1943 2,374,683 Julian May 1,1945 2,496,450 Ehrenstein Feb. 7, 1950 2,530,816 hrenstein Nov. 21, 1950 ,j Ehrenstein Oct. 30, 1951 2,748,149 'eichstein May 29, 1956 2,759,929 Farrar Aug. 21, 1956 2,759,951 Djerassi et al. Aug. 21, 1956 2,774,777. Bjerassi et al. Dec. 18, 1956 2,781,365 Djerassi et al. Feb. 12, 1957 2,788,352; Djerassi et al. Apr. 9, 1957 Djerassi et al. Nov. 18, 1958 QOTHER REFERENCES Sandova;l, A,, Meramontes, L., Rosenkranz, G., Djerassi, 0., and Sondheimer, F.: J. Am. Chem. Soc., vol. 75, 4117-4118 (1953). t

Wilds: J.A.C.S.,;75, 5366-5369, 1953.

Rodd: Chemistryof Carbon Compounds, volume H, part B, page'94 1 ;19 53. l 

5. 17-HYDROXYMETHYL-$4-ESTREN-3-ONE OF THE FOLLOWING FORMULA: 